Slot-head fastener and driver therefor

ABSTRACT

The head of fasteners are provided with an inverted T-slot which is engagable by the T-shaped end of a driver for precluding the accidental or unintentional disengagement of the driver from the fastener-head during insertion or removal thereof.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of the invention relates to screw-type fasteners in general,the heads of which are provided with inverted T-shaped slots which areadapted to be engaged by the T-shaped blade of a driver.

2. Description of the Prior Art

Applicant is aware of the following relevant prior art:

U.S. Pat. Nos. 3,897,812 and 3,923,008 of E. T. Arnn which disclose ascrew driver, the blade end of which is flared outwardly as at 32 toprovide "bites" 30, the overall spacing of which are equal to the widthof a rectangular slot provided in the head of a fastener, said "bites"increasing the effectiveness of the blade in gripping the vertical sidewalls of a slot in the screw head.

U.S. Pat. No. 1,476,653 of J. R. Stanton discloses a screw driver, theblade of which comprises two pairs of reversing beveled faces 14 whichconverge toward a central restricted portion 15, said blade beingadapted to be inserted axially into the transverse groove 17 of a screwhead 16, which groove has a narrow central portion 18 to correspond tothe reversed beveled faces 14 of the blade.

U.S. Pat. No. 3,026,920 of B. H. York discloses a screw driver having adriving tip which is adapted for use with fasteners having undercutdriver-receiving recesses having contours as disclosed in FIGS. 12-18and wherein the driving tip 23 of the screw driver is shaped whereby tobe introduced in an axially, end-wise direction into the recessed headof a screw fastener of the type which is adapted to be countersunk intoa supporting surface.

U.S. Pat. No. 1,997,422 of H. Lorenzen, et al, discloses a countersunkscrew and a driver therefor wherein the driver is adapted to beinterlocked relative to a transverse slot in the screw head. The endface 12 of the driver bit is curved outwardly about a point along thelateral axis of the driver as a center, and the angle of divergence ofthe sides 4 from the vertical is less at the edges than at the middle ofthe bit whereby to provide the edge portions of the bit somewhat thinnerthan the width of the slot in the head of a screw. The end of the bit isadapted to be inserted edgewise into the screw slot, and after the screwhas been completely driven and countersunk into the work, the driver isseparated therefrom by tilting the driver so as to place an edge portionof the face of the bit in the open face of the slot after which thedriver is then manipulated to force the remaining portion of the face ofthe driver bit to become disengaged from the screw slot. Therelationship of the bit and screw slot is such that a screw may bereadily carried on the end of the bit preparatory to a screwingoperation, and at the end of an unscrewing operation, the screw will becarried on the end of the screw driver bit to prevent its beingaccidentally dropped until removed by an operator.

U.S. Pat. No. 2,566,055 of M. Daderko, et al, discloses a screw having aslotted head and a driving tool therefor wherein the screw head isprovided with a transverse slot having a centrally disposed concaveportion 20 and wherein the side walls of the slot are undercut toprovide a dovetail cross section as illustrated in FIGS. 1 and 2thereof. The tip of the screw driver is provided with a bit 28 havingopposite side faces 30 which lie in convergent planes as they recedefrom the shank 26. Faces 30 are flat so that at their convergent endsthey form a relatively narrow edge which is adapted to enter the slot inthe screw head. A lip 32 extends outwardly from one face 30 of bit 28,said lip adapted to engage an undercut portion of the groove in thescrew in substantial alignment with shank 26. The tip of the screwdriver is engageable with and removable from the screw slot by tiltingthe shank of the screw driver as in FIG. 2, whereby to initiallyintroduce extending lip 32 into the slot whereby said lip will bedisposed in contacting relationship with one side of the dovetail grooveof the screw head when the shank of the screw driver is disposed inaxial alignment with the screw.

U.S. Pat. No. 306,492 of G. W. Jackman discloses a screw, the head ofwhich is provided with a pair of transverse splines such as illustratedin FIGS. 2 and 4, the central undercut portions of which are adapted tobe selectively engaged by undercut portions of the jaws of a screwdriver wherein said jaws are movable toward and away from one and otherfrom non-engaging to engaging relationship with the central undercutportions of the pair of splines in the screw head. When the jaws of thedriver are disposed in engagement with the spline portion of the screwhead, accidental or unintentional disengagement of the screw iseffectively precluded.

U.S. Pat. No. 3,825,048 of M. K. Triska discloses a screw head anddriving tool therefor which are releasably coupled together by means ofa pair of radially shiftable anchors each of which have an outwardly anddownwardly tapered outer surface 25, and an inner axial surface 28, saidanchors are held in alternate engagement and disengagement with acomplimentary screw slot by a driver blade 22 shiftable longitudinallybetween said anchors. The screw slot is undercut to prevent displacementof the tapered driving tool from the screw head when the anchors are setin engaged condition and to permit disengagement when the anchors areset in disengaged condition.

U.S. Pat. No. 449,037 of G. T. Chapman discloses a wood screw the headof which is provided with a transversely extending slot, the lowerportion of which is defined by a cylindrical groove the radius of whichis greater than the width of the upper portion of the slot. The reasonfor the slot is to strengthen the head against the tendency of breakageby the screw driver and so that it will retain the filling of puttygenerally applied in finishing interior work.

U.S. Pat. No. 2,301,590 of R. Signorelli discloses a screw driver whichcomprises a pair of laterally spaced bit members 4 the lower end of eachof which terminates in outturned lips 6 which are adapted to be receivedwithin the undercut transverse slot B in the head of a screw, the outerends of each of said bits are forced apart as the bits are shiftedupwardly axially to and along a flat shank 2 which is disposed betweensaid bit members. The bit members are thus forced apart, engage andsubstantially fill the undercut slot of the fastener member.

U.S. Pat. No. 2,684,094 of J. Lissy discloses a non-slip screw driverand screw head wherein the bit of the screw driver is provided withoutwardly flared projections 17 and 18 which are adapted to fillundercut spaces 15 and 16 of the opposite walls 13 and 14 of the slot 12in the screw head 11. The flared projections 17 and 18 of the screwdriver engage the aforesaid undercut space of the side walls of the slotof the head incident to turning of the screw driver after it has beenintroduced in an endwise axial direction into the screw slot.

U.S. Pat. No. 1,782,981 of J. A. Anderson and U.S. Pat. No. 1,741,349 ofR. R. Sullivan each relate to and disclose screw drivers the bits ofwhich have been provided with serrations which are adapted to abutagainst the walls of a slot in the head of a fastener.

U.S. Pat. No. 2,808,087 of R. M. Vaughn; U.S. Pat. No. 3,120,251 of B.H. York; and U.S. Pat. No. 2,677,985 of R. M. Vaughn each relate to anddisclose screw drivers the bits of which are shaped whereby toselectively and interlockingly engage the transverse slots of the headof fasteners wherein the bits of the screw drivers are inserted in anendwise axial direction into the screw head slots.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side plan view of a screw driver which embodies theteachings of the present invention.

FIG. 2 is a bottom view taken on line 2--2 of FIG. 1.

FIG. 3 is a front view of the lower end of the screw driver of FIG. 1.

FIG. 4 is a perspective view of the lower end of a screw driver and thehead portion of a fastener embodying the teachings of the presentinvention.

FIG. 5 is a perspective view illustrating the manner in which thesubject fastener and screw driver are utilized in exerting an upwardscrewing action and/or downward unscrewing action to a fastener.

FIG. 6 is a view similar to FIG. 1 illustrating a modified form of screwdriver.

FIG. 7 is a side view illustrating a modification of the drivehandle forthe screw driver of FIG. 6.

FIG. 8 is a side view partly in section, disclosing a secondmodification of the invention wherein the bit of a driver is associatedwith a socket head for simultaneously engaging both the center slot andthe outer peripheral edges of the head of a fastener.

FIG. 9 is a view taken on line 9--9 of FIG. 8.

FIG. 10 is a view taken on line 10--10 of FIG. 8.

FIG. 11 is a view taken on line 11--11 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings the numeral 20 designates the shank of a driver such asthe screw driver 22 of FIGS. 1 and 5 or the modified drivers 24 and 28of FIGS. 6, 7, and 8.

As best illustrated in FIG. 4, shank 20 terminates in a bit B whichcomprises a substantially rectangular portion 30, the lower end of whichterminates in an outwardly projecting portion 32 wherein portions 30 and32 collectively constitute and define a substantially T-shaped bitwherein the lower portion 32 includes upstanding, substantiallyparallel, laterally spaced side walls 34 which depend from uppertransverse surfaces 36.

The letter F denotes generally a fastener which may comprise a bolt,screw, or other rotatable fastener element which includes a threadedshank S and a head H.

Head H is provided with an inverted T-shaped slot Q which is defined byan elongate upper throat portion T defined by laterally spaced parallelside walls 40 each of which are spaced apart by dimensions slightlygreater than the width of portion 30 of bit B. Throat T is in opencommunication with a wider slot W which, as illustrated, extendscompletely through the head H in a transverse, diametric direction. Ifdesired, the outer ends of the upper and lower slots may be tapered asat 42 for facilitating the sidewise insertion of bit B of a driver 20into the slotted head of a fastener member.

After bit B has been associated with head H, such as, by way of example,as illustrated in FIG. 5, the fastener will be secured to and carried bybit B against accidental or unintentional dislodgment whereby thefastener may be easily manipulated for insertion into a bolt or wherebyto be screwed into an opening in one or more elements to beinterconnected by said fastener.

It will be noted that by reason of the positive interlockingrelationship which is affected between bit B and the slot of thefastener head H, a positive downward, unscrewing force may be applied toa fastener incident to the unscrewing or withdrawal of such a fastenerfrom a "fastened position."

With particular reference now to FIGS. 6 and 7, it will be noted that anincreased turning torque can be applied to shank 22 of a driver by meansof handles 50, one end of each of which terminate in a downwardlyprojecting driver member 52 which is receivable within a complimentarysocket 54 located in the upper end of a drive which includes a shank 20and a bit B.

With particular reference now to FIGS. 8 through 11, I have disclosed acombination driver which comprises the screw driver bit B of FIGS. 1-7in combination with socket J which is secured to and carried by thenoncircular shank 20 and for endwise, axial movement therealong againstthe counterforce of a spring 60 interposed between the lower surface 62of handgrip member 64 and the upper surface 66 of socket J. A snap ring70, or the like, may be secured to and carried by a groove 72 providedin shank 20 whereby to engage the inner surface 74 of socket J, asillustrated in FIG. 8 for limiting the fully advanced position of socketJ with respect to shank 20 and bit B.

Socket J is adapted to be associated with the "flats" 77 of head H of afastener F incident to the elevation or endwise movement thereof againstthe counterforce of spring 60, to an elevated, retracted position J'whereby the lower end 76 of the socket will clear the upper surface 78of fastener head H and for exposing bit B in order that said bit may beinserted by a transverse movement into transverse slot Q in head H offastener F after which socket S may be released from its elevated,retracted position J' to the fully lowered or advance positionillustrated in FIG. 8 whereby a positive turning torque may be appliedin either direction to the head H of fastener F via the centrallydisposed transverse inverted T-shaped slot Q and flats 77.

It will be noted that the aforesaid driving connection or associationwith head H effectively precludes the accidental or unintentionaldisengagement of the driver means from head H of fastener F and thatsaid connection enables an operator to apply an endwise axial force ineither direction to said fastener head.

The upper end of end handgrip 64 may be enlarged as at 65 whereby toaccommodate an internal socket 54 adapted to receive a driver 52 of ahandle 50 for imparting rotary motion to the handgrip.

As clearly illustrated in FIG. 10 the upper end of socket J is providedwith an opening 71 which is dimensioned for sliding engagement with thenoncircular outer surface of shank 20.

From the foregoing it will be noted that I have thus provided simple yethighly effective cooperative means in the head of a fastener and on thebit of a driver whereby the driver is securely, though releasably,secured to a fastener against accidental or unintentional dislodgmenttherefrom and wherein a positive endwise axial force may be applied tothe fastener via the driver without impairing the interconnectionbetween the fastener head and bit of the driver.

What is claimed is:
 1. A slot head fastener and driver thereforcomprising:a slot head fastener having a threaded shank and a head, saidhead being polygonal in shape to have a plurality of flats and having aslot defined therein which is in the shape of an inverted T, said slothaving a first section defined to extend transversely of said head and athroat section intersecting said first section, said throat sectionbeing defined by a pair of laterally spaced parallel side walls whichare spaced apart to define a bit receiving gap therebetween, said slotand said throat having tapered portions to faclitate entrance and exitof a bit into said slot; and a driver for engaging said slot headfastener, said driver including a torquing member having a projectingdriver member thereon, a handgrip member having an internal socketdefined therein at one end thereof, said handgrip member being sized tobe gripped by a user's hand with the user's other hand gripping saidtorquing member, said internal socket being shaped to receive saidtorquing member projecting driver member, a shank connected at one endthereof on another end of said handgrip member, a socket member mountedon said shank to be axially movable thereon and having a shapecorresponding to the shape of said slot head fastener polygonal head toengage said flats to impart turning torque to said fastener, a springmounted on said shank to yieldably bias said socket member towardanother end of said shank, a bit on said shank another end, said bitincluding a rectangular portion sized to be received in said slot headfastener gap, and a projecting portion which is located and sized to bereceived in said head fastener first section, said bit portions forminga T-shaped member which is received in said slotted head fastenerinverted T-shaped slot to form a driving connection between said driverand said fastener whereby torque developed by said driver is imparted tosaid fastener via said socket member and said bit.
 2. A device as calledfor in claim 1, wherein the opposite ends of the inverted T-shaped slotin the fastener head are chamfered.
 3. A device as called for in claim1, wherein the relationship between the inverted T-slot of the fastenerhead and the T-shaped bit of the driver is such that when the bit ishoused within the slot the fastener is securely, though releasably,anchored to and in axial alignment with the driver and whereby tiltingor cocking of the driver relative to the fastener is precluded.
 4. Adevice as called for in claim 3, wherein side, top, and bottom walls ofthe inverted T-shaped slot in the head of the fastener are defined bysubstantially rectangular, flat, co-planar surfaces, and wherein side,top, and bottom walls of the T-shaped bit are defined by substantiallyrectangular, flat, co-planar surfaces, and wherein the relationshipbetween the said slot and bit is such that the bit is inserted into andremoved from the slot only in an endwise direction.
 5. A driver ascalled for in claim 1, wherein the shank includes an offset remote fromthe T-shaped bit, and wherein the spring is disposed between said offsetand the upper surface of the socket.
 6. A driver as called for in claim1, wherein the shank is provided with an abutment adjacent but spacedupwardly from the bit, said abutment engaged by the socket when in itsfully advanced position for limiting the extent of travel of the sockettoward the bit of the shank.
 7. The slot head fastener as defined inclaim 1 wherein said shank is non-circular.
 8. The slot head fastener asdefined in claim 7 wherein said socket has a shank receiving openingdefined therein shaped to correspond to said non-circular shank.
 9. Adriver for a slot head fastener comprising:a shaft with one end thereofforming a drivable end and including an abutment on said shaft, a socketon another end of said shaft and a spring surrounding said shaft andengaging said abutment and said socket to urge said socket toward saidshaft another end, said driver including a fastener engaging bit on saidshaft another end, said bit being T-shaped to cooperatively engage acorrespondingly shaped slot defined in a slot head fastener driven bythe driver, said socket surrounding said bit on all sides except whensaid socket is manually retracted away from said another end against theurging of said spring, said socket being shaped to cooperatively engagethe fastener about the outer periphery of such fastener such that withsaid bit engaged in the slot of the slot head fastener and said socketengaged about the outer periphery of such slot head fastener, suchfastener is held on the driver and disengagement of such fastener fromthe driver is prevented in a direction axially of said shaft as well astransversely of said shaft whereby a fastener may be securely held indriving connection with the driver against accidental or unintentionaldisengagement from the driver.
 10. The driver of claim 9 wherein theslot of the slot head fastener includes a first section extendingtransversely of the head and a second section intersecting the firstsection so that the slot is in the form of an inverted T.
 11. A deviceas called for in claim 9, wherein that end of the fastener-drive whichis remote from the T-shaped bit includes means which are securely,though releasably, engaged by means for augmenting the turning torqueapplied to said driver.
 12. The driver of claim 9 wherein the slot headfastener includes a threaded shank.
 13. The driver of claim 9 furtherincluding a handgrip member on said shaft, said handgrip member beingsized and shaped to be gripped by a user's hand.
 14. The driver of claim13 wherein said shaft has an internal socket defined therein and furtherincluding a torquing member having a driver member thereon which isreceived in said internal socket.
 15. The driver of claim 9 wherein saidsocket has a polygonal shape.
 16. The driver of claim 15 wherein saidshaft is polygonal.
 17. The driver of claim 15 wherein the slot of theslot head fastener includes tapered portions to facilitate entrance andexit of said bit into the slot.
 18. A slot head fastener and drivertherefor comprising:a slot head fastener having a head having a slotdefined therein, said slot including a first section extendingtransversely of said head and a second section intersecting said firstsection so that said slot is in the form of an inverted T, said headhaving an outer periphery; and a driver for engaging said slot headfastener, said driver including a shaft having one end thereof forming adrivable end and further including an abutment thereon, a socket onanother end of said shaft and a spring surrounding said shaft andengaging said abutment and said socket to urge said socket toward saidshaft another end, said driver including a fastener engaging bit on saidshaft another end, said bit being T-shaped to cooperatively engage saidslot head inverted T-shaped slot, said socket being shaped tocooperatively engage said slot head fastener head outer periphery on allsides thereof except when said socket is manually retracted away fromsaid shaft another end against the urging of said spring, said driverbit engaging said slot head fastener slot and said socket engaging saidfastener head outer periphery so that said fastener is held on saiddriver and disengagement of said fastener from said driver is preventedin a direction axially of said shaft by engagement of said T-shaped bitin said inverted T-shaped slot and in a direction transversely of saidshaft by engagement of said socket with said head outer peripherywhereby said fastener is securely held in driving connection with saiddriver against accidental or unintentional disengagement thereof fromsaid driver.
 19. The slot head fastener and driver defined in claim 18wherein said fastener head outer periphery is polygonal.